I tried changing the powertube valve spring but it doesn't reall help at all. I don't have any springs that are the same lenth as the stock hammer main spring though. Ordered a complete nelson spring kit.
Its great that this marker only cost me $130 but all the extra crap is starting to add up. $30 fancy mock silencer tip, $22 extra mag, $40 some first strike rounds, $40 crazy red dot site, and now $10 for a spring kit. After spending $272 I hope I can get this marker to work already.